The present invention relates to semiconductor devices and power source devices using the same, and relates to, for example, a technique effectively applied to a switching power source device for converting a high voltage to a low voltage.
For example, Japanese Patent Laid-Open No. 2009-219184 (Patent Document 1) describes a multi-phase power source, wherein a plurality of semiconductor devices corresponding to the respective phases is coupled in a ring (FIG. 1). Moreover, Japanese Patent Laid-Open No. 2006-50891 (Patent Document 2) describes a multi-phase type DC/DC converter device, wherein a plurality of converter control ICs is used to supply an electric power to a load using different phases, respectively (FIG. 1). Moreover, Japanese Patent Laid-Open No. 2007-135390 (Patent Document 3) describes a multi-phase converter comprising n phase ICs and a control IC supplying a common control signal to each phase IC (FIG. 1, FIG. 2).